There is an ever-increasing need for air sanitation, for air freshening, for air medication, for air deodorizing, and the like, and there is also an ever-increasing need for insect control, for bacterial control, and for similar services. At present, there is a trend for such services and controls by means of airborne vapors, and for convenience of discussion all such services will be grouped under the caption "air treatment" and "air sprays".
In such air treatment by air sprays, it is important that the vapors remain in the air in given effective concentrations. Moreover, the vapors should be non-toxic to humans and to warm-blooded animals.
In the early days of such air treatment, the best procedure that was then available was to use a "hand gun" that atomized a suitable liquid; but improved methods now utilize a pressurized container that uses a product such as "Freon" or the like to propel the liquid into the air in the form of an aerosol. This so-called "active" propellant technique is becoming less desirable for a number of reasons; one of the most important of which is the need for storing a large inventory of such pressurized containers, with the ever-present danger of explosion. Another, and more pressing reason for the discontinuance of this active technique, is the recognition that the propellants are less safe to human beings than had previously been believed. Therefore, the active technique is no longer completely sanctioned.
Another air treatment technique, known as a "static" or "still" technique, does not use a pressurized propellant. Rather, this static technique depends upon the characteristic that many materials--particularly liquid--tend to boil, or evaporate, at ambient conditions of temperature and air pressure, thus providing a localized air treatment.
In an attempt to improve the above static dissemination of the vapors, and to provide a controlled dosage of vapor, a motor-driven fan has been used to disperse the vapors, but the continuous use of such a fan has generally required a wire that is plugged into an electrical outlet, and this wire has become objectionable from an appearance point of view and from a dust-collecting point of view. it also limits the use of such a dispenser to areas that are proximate electrical outlets. In other cases, the motor is energized by a battery, but the battery has to be extremely large, or else it has to be replaced unreasonably often. Further, such continuous blowing of air on the static vapor source generally causes evaporation and usage of the vapor generating material much faster than desired, and at a generally uncontrollable rate, thereby tending to cause undesirable concentrations of the vapors when the vapor source is fresh, and resulting in an undesirably short operative life of the vapor source, requiring the frequent replacement thereof.